lkml.org 
[lkml]   [2019]   [Apr]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v8 7/7] mfd: cros_ec: differentiate SCP from EC by feature bit.
Date
System Companion Processor (SCP) is Cortex M4 co-processor on some
MediaTek platform that can run EC-style firmware. Since a SCP and EC
would both exist on a system, and use the cros_ec_dev driver, we need to
differentiate between them for the userspace, or they would both be
registered at /dev/cros_ec, causing a conflict.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
Changes from v7:
- Address comments in v7.
- Rebase the series onto https://lore.kernel.org/patchwork/patch/1059196/.

Changes from v6:
- No change.

Changes from v5:
- No change.

Changes from v4:
- No change.

Changes from v3:
- No change.

Changes from v2:
- No change.

Changes from v1:
- New patch extracted from Patch 5.
---
drivers/mfd/cros_ec_dev.c | 10 ++++++++++
include/linux/mfd/cros_ec.h | 1 +
include/linux/mfd/cros_ec_commands.h | 2 +-
3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index a3b319913097..5b52b648abf2 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -432,6 +432,16 @@ static int ec_device_probe(struct platform_device *pdev)
ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
}

+ /* Check whether this is actually a SCP rather than an EC. */
+ if (cros_ec_check_features(ec, EC_FEATURE_SCP)) {
+ dev_info(dev, "CrOS SCP MCU detected.\n");
+ /*
+ * Help userspace differentiating ECs from SCP,
+ * regardless of the probing order.
+ */
+ ec_platform->ec_name = CROS_EC_DEV_SCP_NAME;
+ }
+
/*
* Add the class device
* Link to the character device for creating the /dev entry
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 109292a60499..a3e3d6beb19a 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -25,6 +25,7 @@
#define CROS_EC_DEV_NAME "cros_ec"
#define CROS_EC_DEV_PD_NAME "cros_pd"
#define CROS_EC_DEV_ISH_NAME "cros_ish"
+#define CROS_EC_DEV_SCP_NAME "cros_scp"

/*
* The EC is unresponsive for a time after a reboot command. Add a
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index d5bf909af661..80a904ed7d7f 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -884,7 +884,7 @@ enum ec_feature_code {
EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS = 37,
/* EC supports audio codec. */
EC_FEATURE_AUDIO_CODEC = 38,
- /* EC Supports SCP. */
+ /* The MCU is a System Companion Processor (SCP). */
EC_FEATURE_SCP = 39,
/* The MCU is an Integrated Sensor Hub */
EC_FEATURE_ISH = 40,
--
2.21.0.392.gf8f6787159e-goog
\
 
 \ /
  Last update: 2019-04-12 09:20    [W:0.050 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site